[badjones]

Anything that causes sparks near an empty fuel tank ( welding, grinding) is extremely dangerous. Fuel vapour is explosive. To make a permanant repair the tank needs to be removed and flushed with water to remove liquid fuel fully, and then have a patch welded over the hole or braized over the hole, whichever you prefer. PLEASE NOTE. To make the tank safe to weld you need to purge the tank of fuel vapour and the easiest way to do this is to run an tube from a car exhaust into the removed and flushed fuel tank ( must be done outside of course) and run the car for a few minute just before you attempt the repair, and this will purge the tank with a non flamible gas. I always check the tank opening with a lit match at arms length after gassing to make sure all is well before you get close up and personal with the mig welder. I have done many tanks from mainly bikes but cars as well useing this method. For emergency repairs to get you home, mix some ordinary soap with some sand and knead to a firm putty consistancy and plug up the hole with that. Have used this one in the outback down here many times much to the disbelief of those who needed the help. Accidentally sold a car once after doing the soap repair two years earlier and forgot to fix it cause it never let me down. You learn some handy stuff living in the outback. Good luck.